Method of producing storage-battery plates.



'NITED f STATES PATENT ()F IcE.

WILLIAM GARDINER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE Assreu MENTS,TO. HENRY T. CLARKE, an, TRUSTEE.

METHOD OF PRODUCING STORAGE-BATTERY PLATES.

SPEGIFICATION forming part of Letters Patent No. 724,387, dated March31, 11903. Q.

Application filed December 13,1900. Serial No. 39,600. (No specimens.)

Cago, county of Cook, and State of Illinois, have invented certain newand useful Im-.

provements'in Methods of Producing Storage- Battery Plates; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable per- I'o sons skilled in the artto which it appertains I sion between its particles and between it andto make and use the same.

My invention relates to improvements in processes for electrochemicallyforming the;

elements of electric accumulators.

r; The object of my invention is to hasten the time and to ch'eapen theprocess necessary to 1 convert metallic lead platesinto proper conditionto render them active and finally to. subject the said plates to asupplementary 1 :0 process, which I designate a bonding procj *ess, theobject of which is to eliminate the results of the solutions which havebeen used; in the former steps of my process before charging saidelements and to increase the: adhesion between the lead structure ofthe;

elements and the oxid and spongy material formed upon the respectiveelements.

In carrying my process into practice I pursue the following course ormode of proced- .3o 'ure: The plates that are to form the elements ofthe battery-cell comprise an active portion of pure lead and a frame ofan alloy of lead -and antimony or of any metal or alloy that will remainpractically unafiected by the electro- .35 :lytic action. The pure leadplaced in the frame is preferably in a porous or finely-dividedcondition.

In forming the plates or elements I prefer to use pure sheets of lead asone of the electrodes in the electrolyte in which the elements areformed. These sheets of lead I shall designate dummy ,electrodes,because they are not the true electrodes that are designed to become acomponent part of the cell to be produced.

My complete method comprises three steps; but any one of the steps maybe used singly.

The first step consists in subjecting the plates as positive electrodesto the action of a certain electrolyte for the purpose of oxidizing themetallic lead.

tically filled with such material.

The second step consists in subsequently subjecting the oxidized platesas negative electrodes to the action of another electrolyte, and therebyreducing the oxid to spongy lead.-

The third and last step consists in again subjecting the plates aspositive electrodes to a third electrolytic bath. The object of thislatter treatment is to harden and toughen the active material andincrease the cohethe supporting main part or body of the plate. To eachgallon of a ten-per-cent. solution of sulfuric acid I add five ouncesofsulfate of aluminium, five ounces of nitrate of ammonia, and one ounceof oxalic acid.

A small amount of tartaric acid may also be added. Theplates designed'tosubsequently become the positive and negative elements of thebattery-cells are submerged in this bath. Then the positive wire from asource of electric current is connected to the plates, so that thecurrent will enter the plates, pass through the electrolyte, and leavethe negative or dummy be adjusted so that about two or three ami peresper square foot of plate-surface shall pass through the bath. Thedensity of the current, however, will depend upon the condition andconcentration of the electrolyte and possibly upon exterior influences.The current should be continued until the lead plates have beensufficiently oxidized. If there have been previously formed in the leadplate openings in the nature of slots, grooves,

or perforations, these openings will be prac- The plates should be aboutthe color of an equal mixture of salt and pepper when the first step 0has been completed. To convert the oxid to spongy lead, I remove theplates from the electrolyte just described and place them in anelectrolyte which I term the reversing solution. This solution consistsof a solution 5 of sulfuric acid, to each gallon of which is added threeounces of tartaric acid and five ounces of sulfate of magnesia. Afterthe plates have been placed in this electrolyte. the current is directedfrom the dummy elec- Ioo trodesthrough the liquid to the oxidized platesand converts or reduces the oxid in the plates to spongy metallic lead.The current should be adjusted so that approximately fifteen amperes persquare foot of plate-surface will flow through the electrolyte. Thecurrent should be continued until the oxid has been entirely reduced tospongy lead. For the purpose of causing this mass of spongy lead toadhere more tenaciously to the metal support I put the plates thusformed in an electrolyte which with the cooperation of the electriccurrent will bond the two substances and effect a close adhesion betweenthe lead structure and the cohering mass of spongy lead. This I call mybonding solution, which may consist of fifteen ounces of sulfite of sodaand eightounces of sulfid of amo'r fifteen hours, or until they arefully and i completely bonded. After this third and last step has beencompleted the plates should be removed, washed, and finally charged in asulfuric-acid solution having a specific gravity of about 1.2, when theywill be ready for commercial service.

The bonding electrolyte solution may be composed of water and anysoluble sulfur compound having a lower degree of oxidation than sulfuricacid'for example, any of the soluble alkaline sulfids or sulfites,either sin gly or in combination, such as sulfites, hyposulfites, orsulfids of ammonium, magnesium,

sodium, or potassium.

) The effect of my process is to convert the greatest quantity of solidmetallic lead into spongy lead in the shortest space of time and at aminimum of cost and without the usual annoyance of boiling thesolutions, freezing the solutions, pickling the plates, corroding' theplates, and other expensive, tedious, and delaying expedient-s. It alsopreserves the spongy deposit in its primitive state with reference toits hygroscopic nature, so that its available surface is not decreasedwhen it is otherwise converted into a condition to withstand theordinary commercial hard usage. I do not desire to be understood aslimiting my process to the exact proportion of the solutions nor to theexact materials composing such solutions, as any suitable equivalent maybe employed without departing from the gist of myinvent-ion as set outin the claims. Neither does my prccess necessarily include all of thesteps hereinbefore described, as any one of the steps may be used toperform its function and other means maybe used to complete theremaining steps necessary to the completed process.

The terms sulfates, nitrates, oxalates, tartrates, sulfids, and sulfitesas used in the claims are intended to cover any compounds having theseacid radicals, whether in combination with a metal or with hydrogen, thebase being in general immaterial.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is r 1. The process of oxidizing lead plates,which consists in passing an electric current from the plates through anelectrolyte containing in solution three acids one of which is a goodsolvent of lead,vanother a poor solvent of lead, and the third anorganic acid.

2. The process of oxidizing lead plates, which consists in passing anelectric current from the plates through an electrolyte con taining insolution an acid which is a good solvent of lead, an acid which is apoor sol vent of lead, and oxalic acid.

3. The process of oxidizing lead plates, which consists in passing anelectric current from the plates through a solution containing asulfate, a nitrate, and an organic acid.

4. The process of oxidizing lead plates, which consists in passing anelectric current f romthe plates,as positive electrodes, through asolution containing a sulfate, a nitrate, and an oxalate. ,7

5. The process of oxidizing lead plates, which consists in passing anelectric current from the plates,as positive electrodes,through anelectrolyte containing a solution of sulfuric acid,aluminium sulfate,anitrate and an oxalate.

6. The process of reducing oxidized lead plates, which consists inpassing an electric current to the plates through a solution containingsulfuric acid and magnesium sulfate.

7. The process of reducing oxidized lead plates, which consists inpassing an electric current to the plates through a solution containinga sulfate and an organic acid.

8. The process of reducing oxidized lead plates, which consists inpassing an electric current to the plates through a solution containinga sulfate and a tartrate.

9. The processof reducing oxidized lead plates, which consists inpassing an electric current to the plates through a solution containingsulfuric acid, magnesium sulfate, and an organic acid.

10. The process of reducing oxidized lead plates, which consists inpassing an electric current to the plates through a solution containingsulfuric acid, magnesium sulfate, and tartaric acid.

11. The process of bonding the active material of lead storage-batteryplates, which consists in passing an electric current from theplatesthrough a solution containing a soluble sulfur compound having a lowerdegree of oxidation than sulfuric acid.

12. The process of bonding the active material of lead storage-batteryplates, which consists in passing an electric current from the platesthrough a solution containing a soluble sulfur compound having a lowerdegree of oxidation than sulfurous acid.

13. The process of bonding the active material of lead storage-batteryplates, which consists in passing an electric current from theplatesthrough a solution containing a soluble sulfur compound having a lowerdegree of oxidation than sulfuric acid, and a soluble sulfur compoundhaving a lower degree of oxidation than sulfurous acid.

14. The process of bonding the active material of lead storage-batteryplates, which consists in passing an electric current from the platesthrough a solution containing a soluble sulfld and a soluble sulfite.

15. The process of producing lead storagebattery plates, which consistsin passing an electric current from the plates, as positive electrodes,through an electrolyte containing, in solution an acid which is a goodsolvent of lead, an acid which is a poor solvent of lead and an organicacid; and reducing the resulting oxidized lead plates by passing anelectric current to the plates through a solution containing a sulfateand a tartrate.

16. The process of producing lead storagebattery plates, whichconsistsin passing an electric current from the plates, as positive electrodes,through a solution containing a sulfate, a nitrate, and an oxalate; andreducing the resulting oxidized lead plates, by passing an electriccurrent to the plates through a solution containing a sulfate and atartrate,

17. The process of producing storage-battery plates, which consists infirst oxidizing the plates then reducingthe oxidized lead plates bypassing an electric current to said plates through a solution containinga sulfate and a tartrate, and then passing an electric current from thereduced plates through a solution containing a solublesulfur compoundhaving a lower degree of oxidation than sulfuric acid.

18. The process of producing lead storagebattery plates, which consistsin first passing :an electric current from the plates, through asolution containing a sulfate, a nitrate, and

an oxalate; then passing an electric current to said plates through asolution containing a sulfate and a tartrate; and finally passing anelectric current from said plates through a solution containing asoluble sulfur compound having a lower degree of oxidation than sulfuricacid.

19. The process of producing storage-battery plates which consists inpassing an elec'- tric current from the plates, as positive elec trodes,through an electrolyte containing in 6o solution an acid which is a goodsolvent of lead, an acid which is a poor solvent of lead, and an organicacid; then reducing the resulting oxidized lead plates by passing anelectric current to the plates through a solu- '65 tion containing asulfate and a tartrate; and finally passing an electric current from theplates through a solution containing a soluble sulfur compound having alower degree of oxidation than sulfuric acid. 76

20. The process of producing electrodes for electric accumulators orstorage batteries which embraces the'steps of first subjecting theelectrode to the action of an electric cur-' rent while immersed inan'electrolyte which operates in connection with the electric current tooxidize the electrode; then subjecting the electrode to the action of anelectric cur rent while immersed in'a bath containing an electrolytewhich operates in connection with 86 I 7 WILLIAM GARDINER.

Witnesses:

FOREE BAIN, M. F. ALLEN.

